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Oil Catch tank?

29239 Views 93 Replies 22 Participants Last post by  Dawmill
Read over and over the threads, what is the best one out there that does the job?
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Piccies when you do Alan please!:dddc:

I assume the performance gain folks are reffering too will be something along the lines of- if you allow the catch tank to vent to air instead of simply passing back into the TB- then you'll be getting cleaner air into the engine!!!!!????

Yes/no- have i got the right end of the stick!???

All i'd say regarding that is that you have to be careful WHERE you sight vents- as i did used to have a different system for the breather setup- where it basically vented to air instead of through a catch tank & back into the engine- and you could definitely smell oil/engine vapours coming into the car at times when it was like that!!!!!!!!!

All i can say regarding my catch tank setup is that since fitting n modfying it- i no longer see any liquid oil gathering in the TB- it's free n clear- which should hopefully mean the VIS motors are nice n clean too (seen pics of some that were gunked up to hell n that surely can't be good for em!)
Yeah you do get the oil smell, I have piped my catch tank breather hose to the bottom of the engine bay, this has helped since when stationary it does not really get all the way down there and then when moving the gasses should be drawn out by the pipe sticing down just lower than the splash guard. I have not bothered with a filter on it as I dont see the point.

The power is gained by cooler, cleaner air entering the engine, oil vapur reduces octane which even if the engine is not mapped aggesivly for will reduce the burn in the cylinder and make it burn out quicker.
I think we are getting mixed up here about the purpose of the catch tank on the 180.
It's not a performance mod, but a preventative mod, to stop or cut down on the amount of oil that gets into the plenum making an abrasive paste that knackers the vis butterfly ball joints resulting in a new plenum being required. Also to try and protect the 2 vis motors.
Of course if it's possible to plumb it so that it does the above AND gives a performance increase then that's to be welcomed. I am going to change mine to vent to air and blank off the 2 TB inlets to see if it makes a difference. Just waiting for the 2 filters to come now.cool2
Any chance you could post some pics up when you have new setup, there are so many different opinions, but I guess it is down to personal choice here.
I think we all need to see some pics really as the majority of us have all plumbed ours in the same way. Interesting this and thanks for raising the right way. Just need to plumb it in correctly so pics asap would be welcome by the rest of us I think.
It's no different to what we have now. Instead of the pipes terminating at the TB (both crank vents) they terminate in a filter, or in spectres case just a tube to the bottom of the engine bay and 180Boy has his vented straight into the exhaust on his civic, which would satisfy the green brigade.

My filters have come but the car is at work and I'm at home or it would be done now:slap: I intend to use the filters because I want them hiddied (is that a word?) behind the engine cover, so it will basically look like it does now.
On the green car I could smell fumes, but only if stood in traffic for quite a while
Found this picture when I first installed the catch tank on the green zs. The small breather is connected to the catch tank which is in line and connects back to the TB. The larger breather is blanked off, white plug in pipe, the other end from the crank case has a filter on it under the cover.

When I do mine now It will be the same but a filter after the tank and that inlet blocked off on the TB.

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Done it now.
1st photo is before engine cover, so you can see where it's going, 2nd with engine cover.

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Been a busy boy alan?

Looks interesting:)
Been a busy boy alan?

Looks interesting:)
HA HA, it took all of 10 minutes, cut the pipes clamp a filter on the appropriate ends and screw 2 x 10mm bolts into the TB pipes.
Keep us informed how it goes alan:)
Where did you get the filters from Alan, (if from ebay). Looks good.

I was thinking of joinning the large breather hose (the one you have the filter on on the left in your picture) to the other breather hose which i currently have going into the catch tank with a tee piece, and then venting the outlet hose from the catch tank to atmosphere, proberbly with a filter on the end, just for looks if nothing eles. and of course blocking of the two ends on the throttlebody.
Where did you get the filters from Alan, (if from ebay). Looks good.

I was thinking of joinning the large breather hose (the one you have the filter on on the left in your picture) to the other breather hose which i currently have going into the catch tank with a tee piece, and then venting the outlet hose from the catch tank to atmosphere, proberbly with a filter on the end, just for looks if nothing eles. and of course blocking of the two ends on the throttlebody.
Got them from www.800bhp.com £3 something each. Halfords £19.99 LOL.

IIRC I think it was Sheddist that said this. The larger pipe, at higher revs, lets air into the crank case while the small one sucks it back out under vaccuum from the TB. So it probably wouldn't be a good idea to join them together. But saying that if you've removed the source of the vaccuum then the system isn't working as designed so it may still work, who knows?:dunno:

I am going to move the pipework from the tank so it ends in the bottom of the engine bay because I can smell the engine fumes even while driving. if that doesn't work I'll probably put it back to how it was.
Thanks for that Aldon, idea above now scrapped! Hope yours is working for you. May well do same sorta thing.
Well, I've moved the filter from the tank to the bottom of the engine bay, in fact there is a hole in the undertray just by the LH tie down eye just big enough to wedge the filter in so it protrudes out the bottom slightly.

I can honestly say that it does feel a bit perkier now, however it still stinks when stood still, it's ok when on the move though. I might try to move the other filter down to the bottom of the engine bay as well and see how that goes.

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Just to give you an idea,
I run 4 breathers,
2 off the front of the cam cover, its baffled so no oil will be evacuated.
1 off the rear of the cam cover, again its baffled
I off the OE PCV system,
These are all routed back into the catch can (OK drinks flask)
I then run another line to the exhaust for evacuation.
No bad smells in the car but 100% breathing.

This would be over kill for the KV6 set-up BUT it does show the need for these breathers.

If you vent to atmosphere make sure you route the pipe as far back in the engine bay as possible to avoid the smells.

And yes I know, my engine bay needs a clean

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Adding filters to a breather system that vents out is a bad idea, i have been down this route before.

you are filtering oily air through a filter from the inside out, the problem with this is that the filters gunk up from the inside, and from the outside they look ok

after a while they can be severely restricted while still looking nice and clean from the outside, before you know it the system is blocked up, your crankcase pressure has went through the roof and you engine is now leaking oil from anywhere it can to release the pressure.

this has happened to 2 of my cars so far, personally i would advise routing the vent pipe down the back of the engine and underneath the car somewhere, its not 100% "green" although its probably on par running a decat exhaust system.

do it professionally enough and it will never even be detected, do it with silly coloured bling hose and use gaffa tape plus some cable ties to stick it on the car floor, and expect MR MOT man to wonder what is going on

on my last car my vent out pipe looked identical to the aircon drain pipe, only it came from the propshaft area and not from the back of the engine :)

the mod could be considered a performance addition as oil entering the mixture will effect fuel octane ratings, although as i suggested above, i doubt the stock ZS ecu is mapped anywhere near the threshold that this would effect.

my subaru suffered from oil in the inlet as its pumped back in via a PCV valve, and the intercooler was always covered, removing this and the oil contamination allowed me to run a bit more ignition advance :D

and more ignition advance means more smiles :D
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Just to give you an idea,
I run 4 breathers,
2 off the front of the cam cover, its baffled so no oil will be evacuated.
1 off the rear of the cam cover, again its baffled
I off the OE PCV system,
These are all routed back into the catch can (OK drinks flask)
I then run another line to the exhaust for evacuation.
No bad smells in the car but 100% breathing.

This would be over kill for the KV6 set-up BUT it does show the need for these breathers.

If you vent to atmosphere make sure you route the pipe as far back in the engine bay as possible to avoid the smells.

And yes I know, my engine bay needs a clean
Holy cow ed!- that engine bay's errr- busy!!!!!!!
On the KV6 is there any reason why both vents can't be connected to the catch tank as per Andydafrog's suggestion. There is going to be no vaccuum now its removed from the throttle body so both could just vent naturally into the tank, then I could put the vent from the tank to the back of the bay as suggested.:dunno::confused:
On the KV6 is there any reason why both vents can't be connected to the catch tank as per Andydafrog's suggestion. There is going to be no vaccuum now its removed from the throttle body so both could just vent naturally into the tank, then I could put the vent from the tank to the back of the bay as suggested.:dunno::confused:
This is how mine is connected. I put a 3rd hole in the catch tank but you could just join the 2 breathers externally with a 'Y' piece.
This is how mine is connected. I put a 3rd hole in the catch tank but you could just join the 2 breathers externally with a 'Y' piece.
Any pics of your setup Spectre, would be helpful mate:yup:
Hi there, sorry for bringing this back from the dead, but as I bought Deans 180, I now want to fit the catch tank (I bought the car before Dean got round to this mod). I've just got the tank from 800bhp.com and I'd like to do the mod 180boy has done;

If you really want to burn off those vapors then insert a ¼ inch tube into you exhaust system with a 45° slash cut facing away from the gas flow (venturi effect), then run a length of hose from this tube to the catch can, this will vent the crank case vapor and burn it with the exhaust gases on the way out, doesn’t have to be ingested this way, and it keeps your catch can empty as the exhaust sucks from the can.
Even though this might be ott I think it seems like the best idea (and I like OTT)
Just a couple of questions, where abouts in the exhaust does this 1/4" tube need fitting i.e. as far back as poss before/after the cat etc. and will the same rubber tube be ok or is there some extra high temp tube needed?

Thanks Steve
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